The present invention relates generally to containers for holding electronic components and more particularly to containers for holding electrostatic sensitive electronic components.
Containers for holding electronic components are well known in the art. Such containers longitudinally stack such electronic components in an end to end relationship. Typically these containers restrict component rotation within the container and provide for easy slidability of the component longitudinally with respect to the container. One example of a component and a container therefor is a dual in-line package (DIP) electronic component and its container, the DIP tube.
Generally such containers or DIP tubes are transparent rather than opaque. The transparency allows easy identification of and count of electronic components contained therein and allows visual inspection of damage in the form of deformed leads. Some of these transparent containers, DIP tubes, are constructed from a material which contains an antistatic agent to help prevent the electrostatic charging of portions of the electronic component.
Recently, electronic components have become much more sensitive to electrostatic discharge. Several attempts have been made within the electrostatic sensitive electronic component container art to address this problem.
One solution is to add enough of a conductive agent, typically carbon black, to a plastic material forming the container to achieve conductivity and therefore, electrostatic protection of the contained electronic component. Carbon black, however, typically renders the plastic into which it is introduced opaque, namely, black. With an opaque container the electronic components contained therein are no longer visible and it is no longer easy to identify the type of electronic component contained therein, nor to obtain an accurate count without removal of the electronic components and possible subsequent damage thereto.
Similarly containers, DIP tubes, can be constructed from a conductive metal, e.g. aluminum. Typical metals conductive enough to maintain electrostatic protection of the electronic components contained therein. But again, such containers constructed from a metal material are opaque and again, the electronic components contained therein are no longer visible.
Another solution is to provide only a partial transverse electrostatic protection. One particular container manufactured by Wescorp, division of DAL Industries, Inc., 1115 Terra Bella Avenue, Mountain View, Calif., has an open slot extending longitudinally along the top of the DIP tube. A container manufactured by Thielex, 201 Eleventh Street, Piscataway, N.J., is a dual extruded (co-extruded) DIP tube with an opaque conductive body portion and a transparent non-conductive windowpane portion, again along the top of the tube. Both of these containers provide some degree of electrostatic protection to the electronic component contained therein even though neither one completely transversely surrounds the electrostatic sensitive components with a conductive material. Such electrostatic protection may be sufficient for some electronic components in some applications. Both containers allow for visibility of the electronic components contained therein for identifying type and for obtaining an accurate count. Further, such a container with an open slot or a transparent windowpane portion allows for visibility of only a portion of the electronic components contained therein. In both of these containers only the top of the electronic components would be visible, while the remainder of the electronic component would not be visible, e.g., the leads of the electronic component. This consideration is important when containers are used with automatic insertion equipment and the format and quality of the component leads is essential for the proper functioning of the automatic insertion equipment. If the leads of the electronic components cannot be ascertained without extracting the electronic component from the container, either the electrostatic protection of the component or the automatic insertability of the component may be jeopardized.
It is to be noted that none of the prior art containers achieve a fully electrostatic shielded electronic component while allowing a full transverse visual identification of the electronic component.